Fix compile flags for C_LAPACK case

cmake/lapack.cmake

@@ -990,4 +990,9 @@ endforeach ()
 foreach (LA_FILE ${LA_GEN_SRC})
   list(APPEND LA_SOURCES "${NETLIB_LAPACK_DIR}/TESTING/MATGEN/${LA_FILE}")
 endforeach ()
-set_source_files_properties(${LA_SOURCES} PROPERTIES COMPILE_FLAGS "${LAPACK_FFLAGS}")
+
+if (NOT C_LAPACK)
+  set_source_files_properties(${LA_SOURCES} PROPERTIES COMPILE_FLAGS "${LAPACK_FFLAGS}")
+else ()
+  set_source_files_properties(${LA_SOURCES} PROPERTIES COMPILE_FLAGS "${LAPACK_CFLAGS}")
+endif ()