Everywhere: Add sv suffix to strings relying on StringView(char const*)

Each of these strings would previously rely on StringView's char const*
constructor overload, which would call __builtin_strlen on the string.
Since we now have operator ""sv, we can replace these with much simpler
versions. This opens the door to being able to remove
StringView(char const*).

No functional changes.

Kernel/DoubleBuffer.h

@@ -72,7 +72,7 @@ private:
     size_t m_read_buffer_index { 0 };
     size_t m_space_for_writing { 0 };
     bool m_empty { true };
-    mutable Mutex m_lock { "DoubleBuffer" };
+    mutable Mutex m_lock { "DoubleBuffer"sv };
 };
 
 }