[cpp] Fix -Wextra-semi suppression

-Wno-* must appear after -W* to take effect.
In order to do that, The -Wno-* flags must be added
via a config rather than as cflags on the target.

Change-Id: I38f45e7e400936cdc9c7bf041713df4d381f6c3a
Reviewed-on: https://fuchsia-review.googlesource.com/c/third_party/glog/+/602225
Reviewed-by: Tamir Duberstein <tamird@google.com>
1 file changed