misc: Few more resource leak fixes

free after malloc in signals.c
closedir after opendir in diskstat

lib/signals.c

@@ -239,6 +239,7 @@ char *strtosig(const char *restrict s)
     if (isdigit(*p)){
         numsignal = strtol(s,&endp,10);
         if(*endp || endp==s)
+            free(p);
             return NULL; /* not valid */
     }
     if (numsignal){

proc/diskstat.c

@@ -93,6 +93,7 @@ static int scan_for_disks(struct procps_diskstat *info)
                 break;
             }
     }
+    closedir(dirp);
     return 0;
 }