utils: Put crc32 under utils namespace

It conflicts with crc in zlib
Message-Id: <1480918984-4117-2-git-send-email-asias@scylladb.com>

db/commitlog/commitlog.cc

@@ -83,7 +83,7 @@ static logging::logger logger("commitlog");
 using namespace std::chrono_literals;
 
 class crc32_nbo {
-    crc32 _c;
+    utils::crc32 _c;
 public:
     template <typename T>
     void process(T t) {

tests/crc_test.cc

@@ -32,14 +32,14 @@ thread_local disk_error_signal_type general_disk_error;
 
 inline
 uint32_t
-do_compute_crc(crc32& c) {
+do_compute_crc(utils::crc32& c) {
     return c.get();
 }
 
 template <typename T, typename... Rest>
 inline
 uint32_t
-do_compute_crc(crc32& c, const T& val, const Rest&... rest) {
+do_compute_crc(utils::crc32& c, const T& val, const Rest&... rest) {
     c.process(val);
     return do_compute_crc(c, rest...);
 }
@@ -48,7 +48,7 @@ template <typename... T>
 inline
 uint32_t
 compute_crc(const T&... vals) {
-    crc32 c;
+    utils::crc32 c;
     return do_compute_crc(c, vals...);
 }
 

utils/crc.hh

@@ -24,6 +24,8 @@
 #include <cstdint>
 #include <smmintrin.h>
 
+namespace utils {
+
 class crc32 {
     uint32_t _r = 0;
 public:
@@ -95,3 +97,5 @@ public:
         return _r;
     }
 };
+
+}