[net] Fixed macro error in lc-switch.h

Fixed macro error: __LC_SWTICH_H__ -> __LC_SWITCH_H__

components/net/uip/uip/lc-switch.h

@@ -55,7 +55,7 @@
  */
 
 #ifndef __LC_SWITCH_H__
-#define __LC_SWTICH_H__
+#define __LC_SWITCH_H__
 
 /* WARNING! lc implementation using switch() does not work if an
    LC_SET() is done within another switch() statement! */