*: BB_BANNER -> bb_banner (it is not a const or #define)!

correct_password: explain in detail why it is ok to use bb_banner
fsck_minix: make it print bb version, not it's own (outdated/irrelevant) one

Marginal size difference:
   text    data     bss     dec     hex filename
 679119    2700   15632  697451   aa46b busybox_old
 679091    2700   15632  697423   aa44f busybox_unstripped

shell/hush.c

@@ -3787,7 +3787,7 @@ int hush_main(int argc, char **argv)
 			hush_exit(xfunc_error_retval);
 		}
 #if !ENABLE_FEATURE_SH_EXTRA_QUIET
-		printf("\n\n%s hush - the humble shell v"HUSH_VER_STR"\n", BB_BANNER);
+		printf("\n\n%s hush - the humble shell v"HUSH_VER_STR"\n", bb_banner);
 		printf("Enter 'help' for a list of built-in commands.\n\n");
 #endif
 	}