of: fix autoloading due to broken modalias with no 'compatible'

[ Upstream commit b3c0a4da ]

Because of an improper dereference, a stray 'C' character was output to
the modalias when no 'compatible' was specified. This is the case for
some old PowerMac drivers which only set the 'name' property. Fix it to
let them match again.
Reported-by: Mathieu Malaterre <malat@debian.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Tested-by: Mathieu Malaterre <malat@debian.org>
Cc: Philipp Zabel <p.zabel@pengutronix.de>
Cc: Andreas Schwab <schwab@linux-m68k.org>
Fixes: 6543becf ("mod/file2alias: make modalias generation safe for cross compiling")
Cc: stable@vger.kernel.org # v3.9+
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>

scripts/mod/file2alias.c

@@ -653,7 +653,7 @@ static int do_of_entry (const char *filename, void *symval, char *alias)
 	len = sprintf(alias, "of:N%sT%s", (*name)[0] ? *name : "*",
 		      (*type)[0] ? *type : "*");
 
-	if (compatible[0])
+	if ((*compatible)[0])
 		sprintf(&alias[len], "%sC%s", (*type)[0] ? "*" : "",
 			*compatible);