Get rid of other-OS headers in .depend

It looks like blktrace_api.h is being parsed through the depend rule
in Makefile.[FreeBSD|NetBSD|mac] due to the headers being listed in
$(SOURCE) - gcc just ignores missing <> headers while clang generates an
error as it builds the dependency list. Since headers which are
included within source files will be listed as a dependency anyway, I
think they can be removed from $(SOURCE).

Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
diff --git a/Makefile.FreeBSD b/Makefile.FreeBSD
index 9378b19..02ff95d 100644
--- a/Makefile.FreeBSD
+++ b/Makefile.FreeBSD
@@ -33,9 +33,7 @@
 SOURCE = eta.c filehash.c filesetup.c fio.c gettime.c init.c ioengines.c \
 	 io_u.c log.c memory.c mutex.c options.c parse.c rbtree.c smalloc.c \
 	 stat.c parse.c crc/*.c engines/cpu.c engines/mmap.c \
-	 engines/posixaio.c engines/sync.c engines/null.c engines/net.c \
-	 *.h arch/*.h compiler/*.h crc/*.h lib/*.h \
-	 os/indirect.h os/kcompat.h os/os-freebsd.h os/os.h os/syslet.h
+	 engines/posixaio.c engines/sync.c engines/null.c engines/net.c
 
 ifneq ($(findstring $(MAKEFLAGS),s),s)
 ifndef V
diff --git a/Makefile.NetBSD b/Makefile.NetBSD
index 9378b19..02ff95d 100644
--- a/Makefile.NetBSD
+++ b/Makefile.NetBSD
@@ -33,9 +33,7 @@
 SOURCE = eta.c filehash.c filesetup.c fio.c gettime.c init.c ioengines.c \
 	 io_u.c log.c memory.c mutex.c options.c parse.c rbtree.c smalloc.c \
 	 stat.c parse.c crc/*.c engines/cpu.c engines/mmap.c \
-	 engines/posixaio.c engines/sync.c engines/null.c engines/net.c \
-	 *.h arch/*.h compiler/*.h crc/*.h lib/*.h \
-	 os/indirect.h os/kcompat.h os/os-freebsd.h os/os.h os/syslet.h
+	 engines/posixaio.c engines/sync.c engines/null.c engines/net.c
 
 ifneq ($(findstring $(MAKEFLAGS),s),s)
 ifndef V
diff --git a/Makefile.mac b/Makefile.mac
index 25c7fde..3eb20be 100644
--- a/Makefile.mac
+++ b/Makefile.mac
@@ -33,8 +33,7 @@
 SOURCE = eta.c filehash.c filesetup.c fio.c gettime.c init.c ioengines.c \
 	 io_u.c log.c memory.c mutex.c options.c parse.c rbtree.c smalloc.c \
 	 stat.c parse.c crc/*.c engines/cpu.c engines/mmap.c \
-	 engines/posixaio.c engines/sync.c engines/null.c engines/net.c \
-	 *.h */*.h
+	 engines/posixaio.c engines/sync.c engines/null.c engines/net.c
 
 ifneq ($(findstring $(MAKEFLAGS),s),s)
 ifndef V