memcached: add bash to RDEPENDS_memcached

Bashism:
possible bashism in memcached/etc/init.d/memcached line 40 (bash arrays, ${name[0|*|@]}):
if [ -r "${FILES[0]}" ]; then
possible bashism in memcached/etc/init.d/memcached line 42 (bash arrays, ${name[0|*|@]}):
  for FILE in "${FILES[@]}";
possible bashism in memcached/etc/init.d/memcached line 53 (should be VAR="${VAR}foo"):
      CONFIGS+=($NAME)
possible bashism in memcached/etc/init.d/memcached line 54 (should be 'b = a'):
    elif [ "memcached_$2" == "$NAME" ];
possible bashism in memcached/etc/init.d/memcached line 62 (bash arrays, ${name[0|*|@]}):
  if [ ${#CONFIGS[@]} == 0 ];
possible bashism in memcached/etc/init.d/memcached line 71 (bash arrays, ${name[0|*|@]}):
CONFIG_NUM=${#CONFIGS[@]}
possible bashism in memcached/etc/init.d/memcached line 72 ('((' should be '$(('):
for ((i=0; i < $CONFIG_NUM; i++)); do
possible bashism in memcached/etc/init.d/memcached line 73 (bash arrays, ${name[0|*|@]}):
  NAME=${CONFIGS[${i}]}

Signed-off-by: Robert Yang <liezhi.yang@windriver.com>