Fix cbmc-library CMake test configuration

The multi-argument specification is to be used with add_test_pl_profile,
not add_test_pl_tests. Also, remove the spurious first argument that
resulted in 0 tests being found.

Author: tautschnig

regression/cbmc-library/CMakeLists.txt

@@ -3,8 +3,7 @@ add_test_pl_tests(
     "$<TARGET_FILE:cbmc>"
 )
 else()
-add_test_pl_tests(
-    "$<TARGET_FILE:cbmc>"
+add_test_pl_profile(
     "cbmc-library"
     "$<TARGET_FILE:cbmc>"
     "-C;-X;unix"