soc: fsl: qe: make cpm_muram_free() ignore a negative offset

This allows one to simplify callers since they can store a negative
value as a sentinel to indicate "this was never allocated" (or store
the -ENOMEM from an allocation failure) and then call cpm_muram_free()
unconditionally.
Reviewed-by: Timur Tabi <timur@kernel.org>
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Li Yang <leoyang.li@nxp.com>

drivers/soc/fsl/qe/qe_common.c

@@ -176,6 +176,9 @@ void cpm_muram_free(s32 offset)
 	int size;
 	struct muram_block *tmp;
 
+	if (offset < 0)
+		return;
+
 	size = 0;
 	spin_lock_irqsave(&cpm_muram_lock, flags);
 	list_for_each_entry(tmp, &muram_block_list, head) {