libseccomp: fix musl build.

srcpkgs/libseccomp/template

@@ -1,7 +1,7 @@
 # Template file for 'libseccomp'
 pkgname=libseccomp
 version=2.2.1
-revision=1
+revision=2
 build_style=gnu-configure
 hostmakedepends="which automake libtool"
 short_desc="High level interface to the Linux Kernel's seccomp filter"
@@ -11,6 +11,11 @@ license="LGPL-2.1"
 distfiles="https://github.com/seccomp/${pkgname}/archive/v${version}.tar.gz"
 checksum=040251870324b37bdeb2448cd8a54d677fd813104028b37dc4e591e6cf3ecf27
 
+post_extract() {
+	case "$XBPS_TARGET_MACHINE" in
+		*-musl) sed -i '/<linux\/prctl.h>/d' src/system.h;;
+	esac
+}
 pre_configure() {
 	./autogen.sh
 }