Fixed some issues found by winapi_check.

diff --git a/server/context_i386.c b/server/context_i386.c
index 4bc2290..f328542 100644
--- a/server/context_i386.c
+++ b/server/context_i386.c
@@ -15,7 +15,9 @@
 #endif
 #include <unistd.h>
 #include <sys/ptrace.h>
-#include <sys/param.h>
+#ifdef HAVE_SYS_PARAM_H
+# include <sys/param.h>
+#endif
 #include <sys/user.h>
 
 #include "winbase.h"