doc: replace @return by Return:

Sphinx expects Return: and not @return to indicate a return value.

find . -name '*.c' -exec \
sed -i 's/^\(\s\)\*\(\s*\)@return\(\s\)/\1*\2Return:\3/' {} \;

find . -name '*.h' -exec \
sed -i 's/^\(\s\)\*\(\s*\)@return\(\s\)/\1*\2Return:\3/' {} \;

Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
diff --git a/boot/image-fdt.c b/boot/image-fdt.c
index 7aad6d5..692a9ad 100644
--- a/boot/image-fdt.c
+++ b/boot/image-fdt.c
@@ -258,7 +258,7 @@
  * @select: name of FDT to select, or NULL for any
  * @arch: expected FDT architecture
  * @fdt_addrp: pointer to a ulong variable, will hold FDT pointer
- * @return 0 if OK, -ENOPKG if no FDT (but an error should not be reported),
+ * Return: 0 if OK, -ENOPKG if no FDT (but an error should not be reported),
  *	other -ve value on other error
  */