testing/libnih: install under /usr/lib

It is used by upstart and cgmanager, which both are under the /usr
hierarchy, so there's no need to have their dependency outside of it

testing/libnih/APKBUILD

@@ -2,7 +2,7 @@
 # Maintainer:
 pkgname=libnih
 pkgver=1.0.3
-pkgrel=6
+pkgrel=7
 pkgdesc="glib-like library for embedded use"
 url="https://launchpad.net/libnih"
 arch="all"
@@ -30,7 +30,7 @@ build() {
 		--build=$CBUILD \
 		--host=$CHOST \
 		--prefix=/usr \
-		--libdir=/lib \
+		--libdir=/usr/lib \
 		--sysconfdir=/etc \
 		--localstatedir=/var \
 		--disable-nls