Eliminate CMake FindPackageHandleStandardArgs warnings.

CMake complains that the package name does not match when the case
differs, e.g.:
```
CMake Warning (dev) at /usr/share/cmake-3.18/Modules/FindPackageHandleStandardArgs.cmake:273 (message):
  The package name passed to `find_package_handle_standard_args` (UMFPACK)
  does not match the name of the calling package (Umfpack).  This can lead to
  problems in calling code that expects `find_package` result variables
  (e.g., `_FOUND`) to follow a certain pattern.
Call Stack (most recent call first):
  cmake/FindUmfpack.cmake:50 (find_package_handle_standard_args)
  bench/spbench/CMakeLists.txt:24 (find_package)
This warning is for project developers.  Use -Wno-dev to suppress it.
```
Here we rename the libraries to match their true cases.

cmake/FindCHOLMOD.cmake

@@ -1,4 +1,4 @@
-# Cholmod lib usually requires linking to a blas and lapack library.
+# CHOLMOD lib usually requires linking to a blas and lapack library.
 # It is up to the user of this module to find a BLAS and link to it.
 
 if (CHOLMOD_INCLUDES AND CHOLMOD_LIBRARIES)

cmake/FindGoogleHash.cmake

@@ -18,6 +18,6 @@ if(GOOGLEHASH_INCLUDES)
 endif()
 
 include(FindPackageHandleStandardArgs)
-find_package_handle_standard_args(GOOGLEHASH DEFAULT_MSG GOOGLEHASH_INCLUDES GOOGLEHASH_COMPILE)
+find_package_handle_standard_args(GoogleHash DEFAULT_MSG GOOGLEHASH_INCLUDES GOOGLEHASH_COMPILE)
 
 mark_as_advanced(GOOGLEHASH_INCLUDES)

cmake/FindSuperLU.cmake

@@ -90,7 +90,7 @@ endif()
 endif()
 
 include(FindPackageHandleStandardArgs)
-find_package_handle_standard_args(SUPERLU
+find_package_handle_standard_args(SuperLU
                                   REQUIRED_VARS SUPERLU_INCLUDES SUPERLU_LIBRARIES SUPERLU_VERSION_OK
                                   VERSION_VAR SUPERLU_VERSION_VAR)