xbps-src: fix pkg options parsing in package names containing dashes.

When using per-pkg options via etc/conf, all dashes should be replaced by
underscores, i.e:

	XBPS_PKG_OPTIONS_xorg_server=opt,~opt2

common/xbps-src/shutils/common.sh

@@ -90,14 +90,15 @@ msg_normal_append() {
 
 set_build_options() {
     local f j opt optval _optsset pkgopts
-    local -A options
+    local -A options _pkgname
 
     if [ -z "$build_options" ]; then
         return 0
     fi
 
     for f in ${build_options}; do
-        eval pkgopts="\$XBPS_PKG_OPTIONS_${pkgname}"
+        _pkgname=${pkgname//\-/\_}
+        eval pkgopts="\$XBPS_PKG_OPTIONS_${_pkgname}"
         if [ -z "$pkgopts" -o "$pkgopts" = "" ]; then
             pkgopts=${XBPS_PKG_OPTIONS}
         fi