Remove hyphen from rand_name calls in compute tests

data_utils.rand_name() appends randam charactors with a hypen like:

 def rand_name(name=''):
     randbits = str(random.randint(1, 0x7fffffff))
     if name:
         return name + '-' + randbits

So it is not necessary to specify a hypen in caller side.
This patch removes a hypen in compute tests.

Change-Id: Ibed983d75ad9fdbb1f90100863ba0ff1934ab644
diff --git a/tempest/api/compute/keypairs/test_keypairs_negative.py b/tempest/api/compute/keypairs/test_keypairs_negative.py
index 7a1a5e3..6aa0939 100644
--- a/tempest/api/compute/keypairs/test_keypairs_negative.py
+++ b/tempest/api/compute/keypairs/test_keypairs_negative.py
@@ -36,7 +36,7 @@
     @test.idempotent_id('29cca892-46ae-4d48-bc32-8fe7e731eb81')
     def test_keypair_create_with_invalid_pub_key(self):
         # Keypair should not be created with a non RSA public key
-        k_name = data_utils.rand_name('keypair-')
+        k_name = data_utils.rand_name('keypair')
         pub_key = "ssh-rsa JUNK nova@ubuntu"
         self.assertRaises(lib_exc.BadRequest,
                           self._create_keypair, k_name, pub_key)
@@ -45,7 +45,7 @@
     @test.idempotent_id('7cc32e47-4c42-489d-9623-c5e2cb5a2fa5')
     def test_keypair_delete_nonexistent_key(self):
         # Non-existent key deletion should throw a proper error
-        k_name = data_utils.rand_name("keypair-non-existent-")
+        k_name = data_utils.rand_name("keypair-non-existent")
         self.assertRaises(lib_exc.NotFound, self.client.delete_keypair,
                           k_name)
 
@@ -53,7 +53,7 @@
     @test.idempotent_id('dade320e-69ca-42a9-ba4a-345300f127e0')
     def test_create_keypair_with_empty_public_key(self):
         # Keypair should not be created with an empty public key
-        k_name = data_utils.rand_name("keypair-")
+        k_name = data_utils.rand_name("keypair")
         pub_key = ' '
         self.assertRaises(lib_exc.BadRequest, self._create_keypair,
                           k_name, pub_key)
@@ -62,7 +62,7 @@
     @test.idempotent_id('fc100c19-2926-4b9c-8fdc-d0589ee2f9ff')
     def test_create_keypair_when_public_key_bits_exceeds_maximum(self):
         # Keypair should not be created when public key bits are too long
-        k_name = data_utils.rand_name("keypair-")
+        k_name = data_utils.rand_name("keypair")
         pub_key = 'ssh-rsa ' + 'A' * 2048 + ' openstack@ubuntu'
         self.assertRaises(lib_exc.BadRequest, self._create_keypair,
                           k_name, pub_key)
@@ -71,7 +71,7 @@
     @test.idempotent_id('0359a7f1-f002-4682-8073-0c91e4011b7c')
     def test_create_keypair_with_duplicate_name(self):
         # Keypairs with duplicate names should not be created
-        k_name = data_utils.rand_name('keypair-')
+        k_name = data_utils.rand_name('keypair')
         self.client.create_keypair(k_name)
         # Now try the same keyname to create another key
         self.assertRaises(lib_exc.Conflict, self._create_keypair,