build: fix compile warning

Change-Id: Ic698231c25a47d27c15d0c43b6fd777086f991b6
diff --git a/src/contact-storage.cpp b/src/contact-storage.cpp
index 8f37079..c894849 100644
--- a/src/contact-storage.cpp
+++ b/src/contact-storage.cpp
@@ -251,7 +251,7 @@
                      -1, &stmt, 0);
   sqlite3_bind_string(stmt, 1, m_identity.toUri(), SQLITE_TRANSIENT);
   sqlite3_bind_block(stmt, 2, newEndorseCertificate.wireEncode(), SQLITE_TRANSIENT);
-  int res = sqlite3_step(stmt);
+  sqlite3_step(stmt);
 
   sqlite3_finalize(stmt);
 }
@@ -286,9 +286,8 @@
                      -1, &stmt, 0);
   sqlite3_bind_string(stmt, 1, endorserName.toUri(), SQLITE_TRANSIENT);
   sqlite3_bind_string(stmt, 2, certName.toUri(), SQLITE_TRANSIENT);
-  const Block &block = endorseCertificate.wireEncode();
   sqlite3_bind_block(stmt, 3, endorseCertificate.wireEncode(), SQLITE_TRANSIENT);
-  int res = sqlite3_step(stmt);
+  sqlite3_step(stmt);
   sqlite3_finalize(stmt);
   return;
 }
@@ -343,17 +342,17 @@
   sqlite3_stmt *stmt;
   sqlite3_prepare_v2(m_db, "DELETE FROM Contact WHERE contact_namespace=?", -1, &stmt, 0);
   sqlite3_bind_string(stmt, 1, identity, SQLITE_TRANSIENT);
-  int res = sqlite3_step(stmt);
+  sqlite3_step(stmt);
   sqlite3_finalize(stmt);
 
   sqlite3_prepare_v2(m_db, "DELETE FROM ContactProfile WHERE profile_identity=?", -1, &stmt, 0);
   sqlite3_bind_string(stmt, 1, identity, SQLITE_TRANSIENT);
-  res = sqlite3_step(stmt);
+  sqlite3_step(stmt);
   sqlite3_finalize(stmt);
 
   sqlite3_prepare_v2(m_db, "DELETE FROM TrustScope WHERE contact_namespace=?", -1, &stmt, 0);
   sqlite3_bind_string(stmt, 1, identity, SQLITE_TRANSIENT);
-  res = sqlite3_step(stmt);
+  sqlite3_step(stmt);
   sqlite3_finalize(stmt);
 }
 
@@ -486,7 +485,7 @@
                      -1, &stmt, 0);
   sqlite3_bind_int(stmt, 1, (isIntroducer ? 1 : 0));
   sqlite3_bind_string(stmt, 2, identity.toUri(), SQLITE_TRANSIENT);
-  int res = sqlite3_step(stmt);
+  sqlite3_step(stmt);
   sqlite3_finalize(stmt);
   return;
 }
@@ -499,7 +498,7 @@
                      -1, &stmt, 0);
   sqlite3_bind_string(stmt, 1, alias, SQLITE_TRANSIENT);
   sqlite3_bind_string(stmt, 2, identity.toUri(), SQLITE_TRANSIENT);
-  int res = sqlite3_step(stmt);
+  sqlite3_step(stmt);
   sqlite3_finalize(stmt);
   return;
 }
@@ -559,7 +558,7 @@
   sqlite3_bind_string(stmt, 2, type, SQLITE_TRANSIENT);
   sqlite3_bind_block(stmt, 3, data, SQLITE_TRANSIENT);
   sqlite3_bind_string(stmt, 4, dataName, SQLITE_TRANSIENT);
-  int res = sqlite3_step(stmt);
+  sqlite3_step(stmt);
 
   sqlite3_finalize(stmt);
 }