libwatchdog: update yocto override syntax

Signed-off-by: Zhenfei Tai <ztai@google.com>
Change-Id: I918deb41b27e84096a3974d48cb4aa64df35bf20
diff --git a/meta-google/recipes-google/host-power-ctrl/libwatchdog_git.bb b/meta-google/recipes-google/host-power-ctrl/libwatchdog_git.bb
index 771f4b0..a9595c3 100644
--- a/meta-google/recipes-google/host-power-ctrl/libwatchdog_git.bb
+++ b/meta-google/recipes-google/host-power-ctrl/libwatchdog_git.bb
@@ -8,7 +8,7 @@
   file://libwatchdog.sh \
 "
 
-RDEPENDS_${PN} = "bash"
+RDEPENDS:${PN} = "bash"
 
 do_install() {
     install -d ${D}${libexecdir}