Make static usermode helper binaries constant

There are a number of usermode helper binaries that are "hard coded" in
the kernel today, so mark them as "const" to make it harder for someone
to change where the variables point to.

Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Thomas Sailer <t.sailer@alumni.ethz.ch>
Cc: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>
Cc: Johan Hovold <johan@kernel.org>
Cc: Alex Elder <elder@kernel.org>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Cc: Jeff Layton <jlayton@poochiereds.net>
Cc: David Howells <dhowells@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/net/hamradio/baycom_epp.c

@@ -299,7 +299,7 @@ static inline void baycom_int_freq(struct baycom_state *bc)
  *    eppconfig_path should be setable  via /proc/sys.
  */
 
-static char eppconfig_path[256] = "/usr/sbin/eppfpga";
+static char const eppconfig_path[] = "/usr/sbin/eppfpga";
 
 static char *envp[] = { "HOME=/", "TERM=linux", "PATH=/usr/bin:/bin", NULL };
 
@@ -308,8 +308,12 @@ static int eppconfig(struct baycom_state *bc)
 {
 	char modearg[256];
 	char portarg[16];
-        char *argv[] = { eppconfig_path, "-s", "-p", portarg, "-m", modearg,
-			 NULL };
+        char *argv[] = {
+		(char *)eppconfig_path,
+		"-s",
+		"-p", portarg,
+		"-m", modearg,
+		NULL };
 
 	/* set up arguments */
 	sprintf(modearg, "%sclk,%smodem,fclk=%d,bps=%d,divider=%d%s,extstat",