MAINTAINERS: update email addresses to match Gerrit

Yoshie's email address did not match that registered in Gerrit.

Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
Change-Id: I2cb76630e667725a5f63987fde95282305484b50
diff --git a/MAINTAINERS b/MAINTAINERS
index dd135ce..6815bea 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -43,5 +43,5 @@
 -------------------------
 
 M:  Derick Montague <derick.montague@ibm.com> <DerickM[m]!>
-M:  Yoshie Muranaka <yoshie.muranaka@ibm.com>
+M:  Yoshie Muranaka <yoshiemuranaka@gmail.com>
 M:  Gunnar Mills <gmills@linux.vnet.ibm.com> <gunnarm!>