libc/Android.bp: more cleanup.

These files were segregated because they were lacking a little cleanup.
Unfortunately that means this change has to do some of the cleanup, but
that's probably for the best.

Test: treehugger
Change-Id: I2dd33504787fc3313995de99e0745a0df22915b3
diff --git a/libc/stdio/local.h b/libc/stdio/local.h
index a5eb636..62efea1 100644
--- a/libc/stdio/local.h
+++ b/libc/stdio/local.h
@@ -236,7 +236,7 @@
 /* OpenBSD exposes these in <stdio.h>, but we only want them exposed to the implementation. */
 #define __sferror(p) (((p)->_flags & __SERR) != 0)
 #define __sclearerr(p) ((void)((p)->_flags &= ~(__SERR | __SEOF)))
-#define __sgetc(p) (--(p)->_r < 0 ? __srget(p) : (int)(*(p)->_p++))
+#define __sgetc(p) (--(p)->_r < 0 ? __srget(p) : __BIONIC_CAST(static_cast, int, *(p)->_p++))
 
 /* OpenBSD declares these in fvwrite.h, but we share them with C++ parts of the implementation. */
 struct __siov {
@@ -288,7 +288,7 @@
 char* __hldtoa(long double, const char*, int, int*, int*, char**);
 char* __ldtoa(long double*, int, int, int*, int*, char**);
 
-#define WCIO_GET(fp) (_EXT(fp) ? &(_EXT(fp)->_wcio) : (struct wchar_io_data*)0)
+#define WCIO_GET(fp) (_EXT(fp) ? &(_EXT(fp)->_wcio) : NULL)
 
 #define ORIENT_BYTES (-1)
 #define ORIENT_UNKNOWN 0