hush: fix handling of unmatched ${name (without closing '}') -

was eating all remaining input, potentially megabytes.
nofork: save/restore die_jmp too
nofork: use -2222 instead of -111 as "special" return valur for zero
(-111 is used by some applets. -2222 won't fit in exitcode and thus safer)

include/libbb.h

@@ -512,6 +512,7 @@ int wait_nohang(int *wstat);
 /* wait4pid(spawn(argv)) + NOFORK/NOEXEC (if configured) */
 int spawn_and_wait(char **argv);
 struct nofork_save_area {
+	jmp_buf die_jmp;
 	const struct bb_applet *current_applet;
 	int xfunc_error_retval;
 	uint32_t option_mask32;