Avoid space after -include.

This seems to make cpp unhappy. Note that other fixes seems to be needed
to get the build running with gcc2 (missing includes and the like.)

src/tests/add-ons/kernel/file_systems/bfs/btree/Jamfile

@@ -5,7 +5,7 @@ SubDirHdrs $(HAIKU_TOP) src add-ons kernel file_systems bfs ;
 UsePrivateKernelHeaders ;
 UsePrivateHeaders shared ;
 
-rule FPreIncludes { return -include\ $(1:D=$(SUBDIR)) ; }
+rule FPreIncludes { return -include=$(1:D=$(SUBDIR)) ; }
 
 {
 	local defines = [ FDefines USER DEBUG ] ; # _NO_INLINE_ASM