[tools] more cygwin related build fixes

git-svn-id: svn://svn.openwrt.org/openwrt/trunk@15227 3c298f89-4303-0410-b956-a3cf2f4a3e73

tools/include/byteswap.h

-#ifdef __linux__
+#if defined(__linux__) || defined(__CYGWIN__) 
 #include_next <byteswap.h>
 #endif

tools/include/endian.h

 #ifndef __endian_compat_h
 #define __endian_compat_h
 
-#if defined(__linux__)
+#if defined(__linux__) || defined(__CYGWIN__)
 #include <byteswap.h>
 #include_next <endian.h>
 #elif defined(__APPLE__)

tools/include/getline.h

@@ -40,10 +40,16 @@
 static inline ssize_t
 getline(char **outbuf, size_t *outsize, FILE *fp)
 {
-	char *buf;
 	size_t len;
 
+#ifndef __CYGWIN__
+	char *buf;
 	buf = fgetln(fp, &len);
+#else
+	char buf[512];
+	fgets(buf, sizeof(buf), fp);	
+	len = strlen(buf);
+#endif
 	if (buf == NULL)
 		return (-1);