Fixed some of the issues reported by winapi-check.

diff --git a/misc/system.c b/misc/system.c
index d737e8e..2bdd049 100644
--- a/misc/system.c
+++ b/misc/system.c
@@ -157,7 +157,7 @@
 /***********************************************************************
  *           Get80x87SaveSize16   (SYSTEM.7)
  */
-WORD Get80x87SaveSize16(void)
+WORD WINAPI Get80x87SaveSize16(void)
 {
     return 94;
 }
@@ -166,7 +166,7 @@
 /***********************************************************************
  *           Save80x87State16   (SYSTEM.8)
  */
-void Save80x87State16( char *ptr )
+void WINAPI Save80x87State16( char *ptr )
 {
 #ifdef __i386__
     __asm__(".byte 0x66; fsave %0; fwait" : "=m" (ptr) );
@@ -177,7 +177,7 @@
 /***********************************************************************
  *           Restore80x87State16   (SYSTEM.9)
  */
-void Restore80x87State16( const char *ptr )
+void WINAPI Restore80x87State16( const char *ptr )
 {
 #ifdef __i386__
     __asm__(".byte 0x66; frstor %0" : : "m" (ptr) );