Fix memleak and silence Coverity defects

Some of these are not real defects, because we are guaranteed to have valid
context in some functions, and checks are not necessary.
I added the checks anyway in order to silence Coverity on these issues.

One meleak on error condition was fixed in
daemons/ipa-kdb/ipa_kdb_pwdpolicy.c

Silence errors in ipa-client/ipa-getkeytab.c, the code looks wrong, but it is
actually fine as we count before hand so we never actually use the wrong value
that is computed on the last pass when p == 0

Fixes: https://fedorahosted.org/freeipa/ticket/2488

daemons/ipa-kdb/ipa_kdb_passwords.c

@@ -71,6 +71,9 @@ static krb5_error_code ipadb_check_pw_policy(krb5_context context,
     int ret;
 
     ipactx = ipadb_get_context(context);
+    if (!ipactx) {
+        return KRB5_KDB_DBNOTINITED;
+    }
 
     ied = (struct ipadb_e_data *)db_entry->e_data;
     if (ied->magic != IPA_E_DATA_MAGIC) {

daemons/ipa-kdb/ipa_kdb_principals.c

@@ -373,6 +373,9 @@ static krb5_error_code ipadb_parse_ldap_entry(krb5_context kcontext,
     /* proceed to fill in attributes in the order they are defined in
      * krb5_db_entry in kdb.h */
     ipactx = ipadb_get_context(kcontext);
+    if (!ipactx) {
+        return KRB5_KDB_DBNOTINITED;
+    }
     lcontext = ipactx->lcontext;
 
     entry->magic = KRB5_KDB_MAGIC_NUMBER;

daemons/ipa-kdb/ipa_kdb_pwdpolicy.c

@@ -121,6 +121,9 @@ krb5_error_code ipadb_get_ipapwd_policy(struct ipadb_context *ipactx,
 
 done:
     ldap_msgfree(res);
+    if (kerr) {
+        free(pol);
+    }
     return kerr;
 }
 

ipa-client/ipa-getkeytab.c

@@ -211,10 +211,10 @@ static int prep_ksdata(krb5_context krbctx, const char *str,
             if (krberr != 0) {
                 fprintf(stderr,
                         _("Warning unrecognized encryption type: [%s]\n"), t);
-                t = p+1;
+                if (p) t = p + 1;
                 continue;
             }
-            t = p+1;
+            if (p) t = p + 1;
 
             if (!q) {
                 ksdata[j].salttype = KRB5_KDB_SALTTYPE_NORMAL;