Add global variable inSignalContext

This will be used for checking for proper logging when in signal
context.

Signed-off-by: Chase Douglas <chase.douglas@canonical.com>
Reviewed-by: Peter Hutterer <peter.hutterer@who-t.net>
Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>

hw/xfree86/os-support/shared/sigio.c

@@ -99,6 +99,8 @@ xf86SIGIO(int sig)
     int save_errno = errno;     /* do not clobber the global errno */
     int r;
 
+    inSignalContext = TRUE;
+
     ready = xf86SigIOMask;
     to.tv_sec = 0;
     to.tv_usec = 0;
@@ -114,6 +116,8 @@ xf86SIGIO(int sig)
     }
     /* restore global errno */
     errno = save_errno;
+
+    inSignalContext = FALSE;
 }
 
 static int