Fix (?) SCALAPACK_BUILD_TESTING -> SCALAPACK_BUILD_TESTS

Both SCALAPACK_BUILD_TESTS and SCALAPACK_BUILD_TESTING were used.
Only SCALAPACK_BUILD_TESTS is a cache variable (defined in the
main CMakeLists), so I assume all instances have to be
SCALAPACK_BUILD_TESTS

Author: Rickbude

BLACS/CMakeLists.txt

@@ -1,4 +1,4 @@
 add_subdirectory(SRC)
-if(${SCALAPACK_BUILD_TESTING})
+if(${SCALAPACK_BUILD_TESTS})
   add_subdirectory(TESTING)
 endif()

PBLAS/CMakeLists.txt

@@ -1,5 +1,5 @@
 add_subdirectory(SRC)
-if(${SCALAPACK_BUILD_TESTING})
+if(${SCALAPACK_BUILD_TESTS})
   add_subdirectory(TESTING)
   add_subdirectory(TIMING)
 endif()

REDIST/CMakeLists.txt

@@ -1,4 +1,4 @@
 add_subdirectory(SRC)
-if(${SCALAPACK_BUILD_TESTING})
+if(${SCALAPACK_BUILD_TESTS})
   add_subdirectory(TESTING)
 endif()