bullet: use make explicitly

srcpkgs/bullet/template

@@ -6,6 +6,7 @@ wrksrc="bullet3-${version}"
 build_style=cmake
 configure_args="-DBUILD_SHARED_LIBS=1 -DBUILD_BULLET2_DEMOS=0 -DBUILD_CPU_DEMOS=0
  -DBUILD_UNIT_TESTS=0 -DBUILD_OPENGL3_DEMOS=0 -DBUILD_EXTRAS=1 -DINSTALL_EXTRA_LIBS=1"
+make_cmd=make
 makedepends="glu-devel"
 short_desc="3D Collision Detection and Rigid Body Dynamics Library"
 maintainer="John <me@johnnynator.dev>"
@@ -14,6 +15,8 @@ homepage="http://www.bulletphysics.com/Bullet/"
 distfiles="https://github.com/bulletphysics/bullet3/archive/${version}.tar.gz"
 checksum=621b36e91c0371933f3c2156db22c083383164881d2a6b84636759dc4cbb0bb8
 
+export CMAKE_GENERATOR="Unix Makefiles"
+
 post_install() {
 	vlicense LICENSE.txt
 }