fix(ssh): remove -a of generators

All the caller sites seem to be in the context where -a is not needed,
so we can just remove it without modifying the callers.

completions/ssh

@@ -8,7 +8,7 @@ _comp_cmd_ssh__compgen_queries()
         key-plain key-sig protocol-version compression sig ciphers macs
         kexalgorithms pubkeyacceptedkeytypes hostkeyalgorithms
         hostbasedkeytypes hostbasedacceptedkeytypes)
-    _comp_compgen -ac "${cur,,}" -- -W '"${ret[@]}" help"'
+    _comp_compgen -c "${cur,,}" -- -W '"${ret[@]}" help"'
 }
 
 # @since 2.12
@@ -37,7 +37,7 @@ _comp_cmd_ssh__compgen_ciphers()
     [[ ${ret-} ]] || ret=(3des-cbc aes128-cbc aes192-cbc aes256-cbc
         aes128-ctr aes192-ctr aes256-ctr arcfour128 arcfour256 arcfour
         blowfish-cbc cast128-cbc)
-    _comp_compgen -a -- -W '"${ret[@]}"'
+    _comp_compgen -- -W '"${ret[@]}"'
 }
 
 _comp_cmd_ssh__compgen_macs()
@@ -46,7 +46,7 @@ _comp_cmd_ssh__compgen_macs()
     _comp_compgen -v ret -i ssh query "$1" mac
     [[ ${ret-} ]] || ret=(hmac-md5 hmac-sha1 [email protected]
         hmac-ripemd160 hmac-sha1-96 hmac-md5-96)
-    _comp_compgen -a -- -W '"${ret[@]}"'
+    _comp_compgen -- -W '"${ret[@]}"'
 }
 
 # @since 2.12