build: Sort file list

to make build reproducible.
Because filesystems/readdir returns entries in underministic order
and the linker orders functions depending on input order
the resulting fio binary differed across builds
(which we do in disposable VMs for openSUSE)

See https://reproducible-builds.org/ for why this matters.

Signed-off-by: Bernhard M. Wiedemann <bwiedemann@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Makefile

@@ -36,8 +36,8 @@ ifdef CONFIG_GFIO
   PROGS += gfio
 endif
 
-SOURCE :=	$(patsubst $(SRCDIR)/%,%,$(wildcard $(SRCDIR)/crc/*.c)) \
-		$(patsubst $(SRCDIR)/%,%,$(wildcard $(SRCDIR)/lib/*.c)) \
+SOURCE :=	$(sort $(patsubst $(SRCDIR)/%,%,$(wildcard $(SRCDIR)/crc/*.c)) \
+		$(patsubst $(SRCDIR)/%,%,$(wildcard $(SRCDIR)/lib/*.c))) \
 		gettime.c ioengines.c init.c stat.c log.c time.c filesetup.c \
 		eta.c verify.c memory.c io_u.c parse.c mutex.c options.c \
 		smalloc.c filehash.c profile.c debug.c engines/cpu.c \