field_names[x][y] is a pointer

client/mysql.cc: In function 'void build_completion_hash(bool, bool)':
client/mysql.cc:2855:37: error: invalid conversion from 'char' to 'char*' [-fpermissive]
       field_names[i][num_fields*2]= '\0';
Signed-off-by: Daniel Black <daniel.black@au.ibm.com>