lastfm_scrobbler: fetch rbversion from plugin API

This prevents needlessly rebuilding the plugin whenever
RBVERSION changes. (This was introduced by the removal
of CVS $Revision$ tags.)

Change-Id: Ic981c86319edb9c7eb7f0c1de71d4fbaba8989ac

apps/plugins/lastfm_scrobbler.c

@@ -87,8 +87,6 @@ Example
 /* increment this on any code change that effects output */
 #define SCROBBLER_VERSION "1.1"
 
-#define SCROBBLER_REVISION " " RBVERSION " "
-
 #define SCROBBLER_BAD_ENTRY "# FAILED - "
 
 /* longest entry I've had is 323, add a safety margin */
@@ -531,8 +529,8 @@ static int sbl_check_or_open(bool check_only)
             /* write file header */
             rb->fdprintf(fd, "#AUDIOSCROBBLER/" SCROBBLER_VERSION "\n"
                          "#TZ/UNKNOWN\n" "#CLIENT/Rockbox "
-                         TARGET_NAME SCROBBLER_REVISION
-                         HDR_STR_TIMELESS "\n");
+                         TARGET_NAME " %s "
+                         HDR_STR_TIMELESS "\n", rb->rbversion);
             rb->fdprintf(fd, ITEM_HDR);
         }
         else