tests/migration: fix a typo in comment

Signed-off-by: NMao Zhongyi <maozhongyi@cmss.chinamobile.com>
Reviewed-by: NAlex Bennée <alex.bennee@linaro.org>
Reviewed-by: NLaurent Vivier <laurent@vivier.eu>
Reviewed-by: NPhilippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <1d0aa8142a10edf735dac0a3330c46e98b06e8eb.1570208781.git.maozhongyi@cmss.chinamobile.com>
Signed-off-by: NLaurent Vivier <laurent@vivier.eu>

tests/migration/stress.c

@@ -192,7 +192,7 @@ static int stressone(unsigned long long ramsizeMB)
 
     /* We don't care about initial state, but we do want
      * to fault it all into RAM, otherwise the first iter
-     * of the loop below will be quite slow. We cna't use
+     * of the loop below will be quite slow. We can't use
      * 0x0 as the byte as gcc optimizes that away into a
      * calloc instead :-) */
     memset(ram, 0xfe, ramsizeMB * 1024 * 1024);