CMake doesn't have an error function

Instead the spelling is message(FATAL_ERROR "blah"). Although
error("blah") also works because it just complains that error doesn't
exist.

Change-Id: I80384e0198a9013f93f9403d0a4c256749905045
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/63106
Reviewed-by: Bob Beck <bbe@google.com>
Auto-Submit: David Benjamin <davidben@google.com>
Commit-Queue: Bob Beck <bbe@google.com>

crypto/fipsmodule/CMakeLists.txt

@@ -55,7 +55,7 @@ endif()
 
 if(FIPS_DELOCATE)
   if(FIPS_SHARED)
-    error("Can't set both delocate and shared mode for FIPS build")
+    message(FATAL_ERROR "Can't set both delocate and shared mode for FIPS build")
   endif()
 
   add_library(
@@ -134,7 +134,7 @@ if(FIPS_DELOCATE)
   set_target_properties(fipsmodule PROPERTIES LINKER_LANGUAGE C)
 elseif(FIPS_SHARED)
   if(NOT BUILD_SHARED_LIBS)
-    error("FIPS_SHARED set but not BUILD_SHARED_LIBS")
+    message(FATAL_ERROR "FIPS_SHARED set but not BUILD_SHARED_LIBS")
   endif()
 
   add_library(