multiplier suffixes are short, store them directly in struct suffix_mult

function                                             old     new   delta
xstrtoul_range_sfx                                   226     217      -9
xstrtoull_range_sfx                                  291     280     -11
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 0/2 up/down: 0/-20)             Total: -20 bytes
   text    data     bss     dec     hex filename
 669128    2668   13616  685412   a7564 busybox_old
 669108    2668   13616  685392   a7550 busybox_unstripped

coreutils/dd.c

@@ -25,7 +25,7 @@ static const struct suffix_mult dd_suffixes[] = {
 	{ "M", 1048576 },
 	{ "GD", 1000000000 },
 	{ "G", 1073741824 },
-	{ NULL, 0 }
+	{ }
 };
 
 struct globals {

coreutils/head.c

@@ -25,7 +25,7 @@ static const struct suffix_mult head_suffixes[] = {
 	{ "b", 512 },
 	{ "k", 1024 },
 	{ "m", 1024*1024 },
-	{ NULL, 0 }
+	{ }
 };
 #endif
 

coreutils/od_bloaty.c

@@ -981,7 +981,7 @@ parse_old_offset(const char *s, off_t *offset)
 	static const struct suffix_mult Bb[] = {
 		{ "B", 1024 },
 		{ "b", 512 },
-		{ NULL, 0 }
+		{ }
 	};
 	char *p;
 	int radix;
@@ -1204,7 +1204,7 @@ int od_main(int argc, char **argv)
 		{ "b", 512 },
 		{ "k", 1024 },
 		{ "m", 1024*1024 },
-		{ NULL, 0 }
+		{ }
 	};
 	unsigned opt;
 	int l_c_m;

coreutils/sleep.c

@@ -29,7 +29,7 @@ static const struct suffix_mult sfx[] = {
 	{ "m", 60 },
 	{ "h", 60*60 },
 	{ "d", 24*60*60 },
-	{ NULL, 0 }
+	{ }
 };
 #endif
 

coreutils/split.c

@@ -20,7 +20,7 @@ static const struct suffix_mult split_suffices[] = {
 #if ENABLE_FEATURE_SPLIT_FANCY
 	{ "g", 1024*1024*1024 },
 #endif
-	{ NULL, 0 }
+	{ }
 };
 
 /* Increment the suffix part of the filename.

coreutils/stty.c

@@ -524,10 +524,10 @@ static void display_window_size(const int fancy)
 }
 
 static const struct suffix_mult stty_suffixes[] = {
-	{"b",  512 },
-	{"k",  1024},
-	{"B",  1024},
-	{NULL, 0   }
+	{ "b",  512 },
+	{ "k", 1024 },
+	{ "B", 1024 },
+	{ }
 };
 
 static const struct mode_info *find_mode(const char *name)

coreutils/tail.c

@@ -30,7 +30,7 @@ static const struct suffix_mult tail_suffixes[] = {
 	{ "b", 512 },
 	{ "k", 1024 },
 	{ "m", 1024*1024 },
-	{ NULL, 0 }
+	{ }
 };
 
 struct globals {