remove duplicate license that already exists in meta-oe

Signed-off-by: Derek Straka <derek@asterius.io>

conf/layer.conf

@@ -8,7 +8,5 @@ BBFILE_COLLECTIONS += "rust-layer"
 BBFILE_PATTERN_rust-layer := "^${LAYERDIR}/"
 BBFILE_PRIORITY_rust-layer = "7"
 
-LICENSE_PATH += "${LAYERDIR}/files/common-licenses"
-
 # Override security flags
 require conf/distro/include/rust_security_flags.inc