kbuild: fix typos (s/bin_shipped/bin.o_shipped/) in Documentation

The text always mentions ...bin.o_shipped, just the example makefiles
actually use ...bin_shipped. It was corrected in one place some time
ago, these ones seem to have been forgotten.
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>

Documentation/kbuild/modules.txt

@@ -253,7 +253,7 @@ following files:
 
 		# Module specific targets
 		genbin:
-			echo "X" > 8123_bin_shipped
+			echo "X" > 8123_bin.o_shipped
 
 
 	In example 2, we are down to two fairly simple files and for simple
@@ -279,7 +279,7 @@ following files:
 
 		# Module specific targets
 		genbin:
-			echo "X" > 8123_bin_shipped
+			echo "X" > 8123_bin.o_shipped
 
 		endif