File fix-pkgconfig-includedir.patch of Package libbullet

diff -Naur a/bullet.pc.cmake b/bullet.pc.cmake
--- a/bullet.pc.cmake	2019-12-20 19:26:32.000000000 -0500
+++ b/bullet.pc.cmake	2020-02-01 00:18:39.859704707 -0500
@@ -1,7 +1,7 @@
 prefix=@CMAKE_INSTALL_PREFIX@
 exec_prefix=${prefix}
 libdir=${exec_prefix}/@LIB_DESTINATION@
-includedir=${prefix}/@INCLUDE_INSTALL_DIR@
+includedir=${prefix}/include/bullet
 
 Name: bullet
 Description: Bullet Continuous Collision Detection and Physics Library