btrfs-progs: build: use -std=gnu89 for sparse

Sparse does not seem to support gnu90 that we'd like to keep for the
regular build. Use gnu89 for C=1 build.

Signed-off-by: David Sterba <dsterba@suse.com>

diff --git a/Makefile b/Makefile
index 2e8d932..243701a 100644 (file)
--- a/Makefile
+++ b/Makefile
@@ -62,8 +62,9 @@ DEBUG_LDFLAGS :=
 TOPDIR := $(shell pwd)
 
 # Common build flags
+CSTD = -std=gnu90
 CFLAGS = $(SUBST_CFLAGS) \
-        -std=gnu90 \
+        $(CSTD) \
         -include config.h \
         -DBTRFS_FLAT_INCLUDES \
         -D_XOPEN_SOURCE=700  \
@@ -262,6 +263,7 @@ ifdef C
                        grep -v __SIZE_TYPE__ > $(check_defs))
        check = $(CHECKER)
        check_echo = echo
+       CSTD = -std=gnu89
 else
        check = true
        check_echo = true