kbuild: Move depmod call to a separate script

Do not bloat the Makefile with multiline shell statements. No
user-visible change intended.

Signed-off-by: Michal Marek <mmarek@suse.cz>

scripts/depmod.sh

@@ -0,0 +1,25 @@
+#!/bin/sh
+#
+# A depmod wrapper used by the toplevel Makefile
+
+if test $# -ne 2; then
+	echo "Usage: $0 /sbin/depmod <kernelrelease>" >&2
+	exit 1
+fi
+DEPMOD=$1
+KERNELRELEASE=$2
+
+if ! "$DEPMOD" -V 2>/dev/null | grep -q module-init-tools; then
+	echo "Warning: you may need to install module-init-tools" >&2
+	echo "See http://www.codemonkey.org.uk/docs/post-halloween-2.6.txt" >&2
+	sleep 1
+fi
+
+if ! test -r System.map -a -x "$DEPMOD"; then
+	exit 0
+fi
+set -- -ae -F System.map
+if test -n "$INSTALL_MOD_PATH"; then
+	set -- "$@" -b "$INSTALL_MOD_PATH"
+fi
+exec "$DEPMOD" "$@" "$KERNELRELEASE"