Change BB_EXTRA_VERSION: now it needs to contain any spaces/parenthesis

Before this change, BB_EXTRA_VERSION of "" resulted in:

	"BusyBox v1.28.0.git () multi-call binary"

message, after the fix it is:

	"BusyBox v1.28.0.git multi-call binary"

While at it, eliminate BB_BT and BANNER single-use macros.

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

Makefile.flags

@@ -15,7 +15,7 @@ CPPFLAGS += \
 	-include include/autoconf.h \
 	-D_GNU_SOURCE -DNDEBUG \
 	$(if $(CONFIG_LFS),-D_LARGEFILE_SOURCE -D_LARGEFILE64_SOURCE -D_FILE_OFFSET_BITS=64) \
-	-D"BB_VER=KBUILD_STR($(BB_VER))" -DBB_BT=AUTOCONF_TIMESTAMP
+	-D"BB_VER=KBUILD_STR($(BB_VER))"
 
 CFLAGS += $(call cc-option,-Wall,)
 CFLAGS += $(call cc-option,-Wshadow,)

libbb/messages.c

@@ -14,12 +14,10 @@
 
 /* allow version to be extended, via CFLAGS */
 #ifndef BB_EXTRA_VERSION
-#define BB_EXTRA_VERSION BB_BT
+#define BB_EXTRA_VERSION " ("AUTOCONF_TIMESTAMP")"
 #endif
 
-#define BANNER "BusyBox v" BB_VER " (" BB_EXTRA_VERSION ")"
-
-const char bb_banner[] ALIGN1 = BANNER;
+const char bb_banner[] ALIGN1 = "BusyBox v" BB_VER BB_EXTRA_VERSION;
 
 
 const char bb_msg_memory_exhausted[] ALIGN1 = "out of memory";