Avoid if() quoted auto-dereference
Avoid if() quoted auto-dereference

When testing CMAKE_C_COMPILER_ID values, do not explicitly dereference
or quote the variable.  We want if() to auto-dereference the variable
and not its value.  While at it, use STREQUAL instead of MATCHES.

Change-Id: I7098fb6474500605b0fe78d764dd2d8afe385f50

chuckatkins/KWSys,chuckatkins/KWSys,chuckatkins/KWSys,chuckatkins/KWSys