Only Windows doesn't have <sys/uio.h>.

This should probably be in libcutils instead, so code that needs to
care about Windows can use readv/writev.

Change-Id: I7c2ceec3f742cee0e44f69fd4c88459376bd0e08

include/log/uio.h

@@ -14,20 +14,23 @@
  * limitations under the License.
  */
 
-//
-// implementation of sys/uio.h for platforms that don't have it (Win32)
-//
 #ifndef _LIBS_CUTILS_UIO_H
 #define _LIBS_CUTILS_UIO_H
 
-#ifdef HAVE_SYS_UIO_H
+#if !defined(_WIN32)
+
 #include <sys/uio.h>
+
 #else
 
 #ifdef __cplusplus
 extern "C" {
 #endif
 
+//
+// Implementation of sys/uio.h for Win32.
+//
+
 #include <stddef.h>
 
 struct iovec {
@@ -42,7 +45,7 @@ extern int  writev( int  fd, const struct iovec*  vecs, int  count );
 }
 #endif
 
-#endif /* !HAVE_SYS_UIO_H */
+#endif
 
 #endif /* _LIBS_UTILS_UIO_H */
 

liblog/uio.c

@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-#ifndef HAVE_SYS_UIO_H
+#if defined(_WIN32)
 
 #include <log/uio.h>
 #include <unistd.h>
@@ -73,4 +73,4 @@ Exit:
     return total;
 }
 
-#endif /* !HAVE_SYS_UIO_H */
+#endif