avoid using strok - eliminates use of hidden global variable

function                                             old     new   delta
udhcp_str2optset                                     616     650     +34
setpriv_main                                         950     975     +25
switch_root_main                                     688     706     +18
parse                                                958     970     +12
getopt_main                                          622     628      +6
parse_resolvconf                                     302     306      +4
mpstat_main                                         1139    1142      +3
static.p                                               4       -      -4
cdcmd                                                717     702     -15
strtok                                               148       -    -148
------------------------------------------------------------------------------
(add/remove: 0/3 grow/shrink: 7/1 up/down: 102/-167)          Total: -65 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
diff --git a/procps/mpstat.c b/procps/mpstat.c
index 52a436a..c78c1f0 100644
--- a/procps/mpstat.c
+++ b/procps/mpstat.c
@@ -923,7 +923,7 @@
 		char *t;
 		G.p_option = 1;
 
-		for (t = strtok(opt_set_cpu, ","); t; t = strtok(NULL, ",")) {
+		for (t = strtok_r(opt_set_cpu, ",", &opt_set_cpu); t; t = strtok_r(NULL, ",", &opt_set_cpu)) {
 			if (strcmp(t, "ALL") == 0) {
 				/* Select every CPU */
 				memset(G.cpu_bitmap, 0xff, G.cpu_bitmap_len);