busybox: move passwd applet to /bin

busybox currently installs passwd into /usr/bin which prevents its
'full' shadow-utils variant from being installed.
Move the passwd applet to /bin to avoid that collision.
shadow also provides /usr/bin/login which doesn't collide with busybox
as the busybox login applet is installed at /bin/login.

Signed-off-by: Daniel Golle <daniel@makrotopia.org>

package/utils/busybox/patches/510-move-passwd-applet-to-bin.patch

@@ -0,0 +1,11 @@
+--- a/loginutils/passwd.c
++++ b/loginutils/passwd.c
+@@ -23,7 +23,7 @@
+ //config:	  With this option passwd will refuse new passwords which are "weak".
+ 
+ //applet:/* Needs to be run by root or be suid root - needs to change /etc/{passwd,shadow}: */
+-//applet:IF_PASSWD(APPLET(passwd, BB_DIR_USR_BIN, BB_SUID_REQUIRE))
++//applet:IF_PASSWD(APPLET(passwd, BB_DIR_BIN, BB_SUID_REQUIRE))
+ 
+ //kbuild:lib-$(CONFIG_PASSWD) += passwd.o
+