config.mak.uname: remove SPARSE_FLAGS setting for cygwin

Since commit f66450a ("cygwin: Remove the Win32 l/stat() implementation",
2013-06-22), the cygwin build has not used the WIN32 API/header files.
This means that the '-isystem /usr/include/w32api' option to sparse is
no longer necessary (to allow sparse to find the WIN32 header files).
In addition, the '-Wno-one-bit-signed-bitfield' option can be removed,
since the warning suppressed by that option was only provoked by a WIN32
header file.

Signed-off-by: Ramsay Jones <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>

Author: ramsay-jones

config.mak.uname

@@ -182,7 +182,6 @@ ifeq ($(uname_O),Cygwin)
 	NO_ST_BLOCKS_IN_STRUCT_STAT = YesPlease
 	X = .exe
 	UNRELIABLE_FSTAT = UnfortunatelyYes
-	SPARSE_FLAGS = -isystem /usr/include/w32api -Wno-one-bit-signed-bitfield
 	OBJECT_CREATION_USES_RENAMES = UnfortunatelyNeedsTo
 	MMAP_PREVENTS_DELETE = UnfortunatelyYes
 	COMPAT_OBJS += compat/cygwin.o