staging: usbip: userspace: fix header installation bug

A bug that I created due to using simply expanding variables in the
makefiles. Although only unexpanded paths are at issue here, I decided
to use recursively expanding variables on all of the parameterized
values.
Signed-off-by: Nmatt mooney <mfm@muteddisk.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

drivers/staging/usbip/userspace/Makefile.am

 SUBDIRS := libsrc src
-includedir := @includedir@/usbip
+includedir = @includedir@/usbip
 include_HEADERS := $(addprefix libsrc/, \
 		     usbip_common.h vhci_driver.h usbip_host_driver.h)
 

drivers/staging/usbip/userspace/libsrc/Makefile.am

-libusbip_la_CPPFLAGS := -DUSBIDS_FILE='"@USBIDS_DIR@/usb.ids"'
-libusbip_la_CFLAGS   := @EXTRA_CFLAGS@
-libusbip_la_LDFLAGS  := -version-info @LIBUSBIP_VERSION@
+libusbip_la_CPPFLAGS = -DUSBIDS_FILE='"@USBIDS_DIR@/usb.ids"'
+libusbip_la_CFLAGS   = @EXTRA_CFLAGS@
+libusbip_la_LDFLAGS  = -version-info @LIBUSBIP_VERSION@
 
 lib_LTLIBRARIES := libusbip.la
 libusbip_la_SOURCES := names.c names.h usbip_host_driver.c usbip_host_driver.h \

drivers/staging/usbip/userspace/src/Makefile.am

-AM_CPPFLAGS := -I$(top_srcdir)/libsrc -DUSBIDS_FILE='"@USBIDS_DIR@/usb.ids"'
-AM_CFLAGS   := @EXTRA_CFLAGS@ @PACKAGE_CFLAGS@
-LDADD       := $(top_builddir)/libsrc/libusbip.la @PACKAGE_LIBS@
+AM_CPPFLAGS = -I$(top_srcdir)/libsrc -DUSBIDS_FILE='"@USBIDS_DIR@/usb.ids"'
+AM_CFLAGS   = @EXTRA_CFLAGS@ @PACKAGE_CFLAGS@
+LDADD       = $(top_builddir)/libsrc/libusbip.la @PACKAGE_LIBS@
 
 sbin_PROGRAMS := usbip usbipd