fastboot: Allow searching for needed dynamic libs in '.' (F2FS)

Currently the default rpath includes $ORIGIN/../lib
So we throw in '.' which should help distributions of fastboot.

readelf -d $(which fastboot)|grep RPATH
 0x0000000f (RPATH) Library rpath: [$ORIGIN/../lib:.]

Bug: 15731906
Change-Id: I2f4345d178e5b3c87f6f159faf105ae30f3b52eb
Signed-off-by: JP Abgrall <jpa@google.com>
diff --git a/fastboot/Android.mk b/fastboot/Android.mk
index 0238404..08854cf 100644
--- a/fastboot/Android.mk
+++ b/fastboot/Android.mk
@@ -66,7 +66,7 @@
 ifeq ($(HOST_OS),linux)
 # libf2fs_dlutils_host will dlopen("libf2fs_fmt_host_dyn")
 LOCAL_CFLAGS += -DUSE_F2FS
-LOCAL_LDFLAGS += -ldl -rdynamic
+LOCAL_LDFLAGS += -ldl -rdynamic -Wl,-rpath,.
 LOCAL_REQUIRED_MODULES := libf2fs_fmt_host_dyn
 # The following libf2fs_* are from system/extras/f2fs_utils,
 # and do not use code in external/f2fs-tools.