samples: Make fs-monitor depend on libc and headers

Prevent build errors when headers or libc are not available, such as on
kernel build bots, like the below:

samples/fanotify/fs-monitor.c:7:10: fatal error: errno.h: No such file
or directory
  7 | #include <errno.h>
    |          ^~~~~~~~~

Link: https://lore.kernel.org/r/[email protected]
Suggested-by: Guenter Roeck <[email protected]>
Tested-by: Guenter Roeck <[email protected]>
Signed-off-by: Gabriel Krisman Bertazi <[email protected]>
Signed-off-by: Jan Kara <[email protected]>

Author: krisman-at-collabora

samples/Kconfig

@@ -122,7 +122,7 @@ config SAMPLE_CONNECTOR
 
 config SAMPLE_FANOTIFY_ERROR
 	bool "Build fanotify error monitoring sample"
-	depends on FANOTIFY
+	depends on FANOTIFY && CC_CAN_LINK && HEADERS_INSTALL
 	help
 	  When enabled, this builds an example code that uses the
 	  FAN_FS_ERROR fanotify mechanism to monitor filesystem