Coccinelle: Add support to the SPFLAGS variable

The SPFLAGS variable allows to pass additional options
to spatch, e.g. -use_glimpse.

Signed-off-by: Nicolas Palix <nicolas.palix@imag.fr>
Signed-off-by: Michal Marek <mmarek@suse.cz>

scripts/coccicheck

@@ -11,7 +11,7 @@ else
 	VERBOSE=0
 fi
 
-FLAGS="-very_quiet"
+FLAGS="$SPFLAGS -very_quiet"
 
 # spatch only allows include directories with the syntax "-I include"
 # while gcc also allows "-Iinclude" and "-include include"