mmc-utils: restore FORTIFY_SOURCE=2

The previous commit
ba4338d mmc-utils: don't set -D_FORTIFY_SOURCE in Makefile
applied the global value of FORITFY_SOURCE also to mmc-utils.
As the package was meant to be built with FORTIFY_SOURCE upstream,
restore that behaviour and make it play nice with the global setting
by undefining the macro before defining it.

Signed-off-by: Daniel Golle <daniel@makrotopia.org>

utils/mmc-utils/patches/001-dont-set-fortify-source-in-makefile.patch → utils/mmc-utils/patches/001-properly-set-fortify-source-in-makefile.patch

@@ -5,7 +5,7 @@ Index: mmc-utils-f4eb241519f8d500ce6068a70d2389be39ac5189/Makefile
 @@ -1,5 +1,5 @@
  CC ?= gcc
 -AM_CFLAGS = -D_FILE_OFFSET_BITS=64 -D_FORTIFY_SOURCE=2
-+AM_CFLAGS = -D_FILE_OFFSET_BITS=64
++AM_CFLAGS = -D_FILE_OFFSET_BITS=64 -U_FORTIFY_SOURCE -D_FORTIFY_SOURCE=2
  CFLAGS ?= -g -O2
  objects = \
  	mmc.o \