MAINTAINERS: update Andrey Konovalov's email address

Use my personal email address.

Link: https://lkml.kernel.org/r/b0ec98dabbc12336c162788f5ccde97045a0d65e.1613150186.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Marco Elver <elver@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Author: xairy

MAINTAINERS

@@ -9584,7 +9584,7 @@ F:	scripts/kconfig/
 
 KCOV
 R:	Dmitry Vyukov <dvyukov@google.com>
-R:	Andrey Konovalov <andreyknvl@google.com>
+R:	Andrey Konovalov <andreyknvl@gmail.com>
 L:	kasan-dev@googlegroups.com
 S:	Maintained
 F:	Documentation/dev-tools/kcov.rst