meta-phosphor: fix S with trailing slash

Upstream OE added a warning when S has a trailing slash.  Remove the
trailing S from the flagged recipes to avoid the warning.

(From meta-phosphor rev: 29d26b3f9b014d156846b0b6e0a1e2f65510b328)

Change-Id: I932d3758c5080a335970dca2e462fe6accd06928
Signed-off-by: Brad Bishop <bradleyb@fuzziesquirrel.com>
Signed-off-by: Andrew Geissler <geissonator@yahoo.com>
diff --git a/meta-phosphor/recipes-phosphor/ipmi/phosphor-ipmi-ipmb_git.bb b/meta-phosphor/recipes-phosphor/ipmi/phosphor-ipmi-ipmb_git.bb
index 3c2f590..c3028ab 100644
--- a/meta-phosphor/recipes-phosphor/ipmi/phosphor-ipmi-ipmb_git.bb
+++ b/meta-phosphor/recipes-phosphor/ipmi/phosphor-ipmi-ipmb_git.bb
@@ -17,6 +17,6 @@
            boost \
            nlohmann-json"
 
-S = "${WORKDIR}/git/"
+S = "${WORKDIR}/git"
 inherit cmake systemd
 FILES_${PN} += "/usr/share/ipmbbridge/ipmb-channels.json"