msi: Add a break to a switch statement

[Andrew Talbot]

Changelog:
    msi: Add a break to a switch statement.

diff --git a/dlls/msi/record.c b/dlls/msi/record.c
index 7acbfc7..1dace78 100644
--- a/dlls/msi/record.c
+++ b/dlls/msi/record.c
@@ -494,6 +494,7 @@ UINT MSI_RecordGetStringW(MSIRECORD *rec, UINT iField,
     case MSIFIELD_NULL:
         if( szValue && *pcchValue > 0 )
             szValue[0] = 0;
+        break;
     default:
         break;
     }