Kernel: Remove OOM unsafe DoubleBuffer constructor

Remove this dangerous and now unused constructor.

Kernel/DoubleBuffer.cpp

@@ -26,11 +26,6 @@ OwnPtr<DoubleBuffer> DoubleBuffer::try_create(size_t capacity)
     return adopt_own_if_nonnull(new (nothrow) DoubleBuffer(capacity, storage.release_nonnull()));
 }
 
-DoubleBuffer::DoubleBuffer(size_t capacity)
-    : DoubleBuffer(capacity, KBuffer::try_create_with_size(capacity * 2, Region::Access::Read | Region::Access::Write, "DoubleBuffer").release_nonnull())
-{
-}
-
 DoubleBuffer::DoubleBuffer(size_t capacity, NonnullOwnPtr<KBuffer> storage)
     : m_write_buffer(&m_buffer1)
     , m_read_buffer(&m_buffer2)

Kernel/DoubleBuffer.h

@@ -17,7 +17,6 @@ namespace Kernel {
 class DoubleBuffer {
 public:
     [[nodiscard]] static OwnPtr<DoubleBuffer> try_create(size_t capacity = 65536);
-    explicit DoubleBuffer(size_t capacity = 65536);
     [[nodiscard]] KResultOr<size_t> write(const UserOrKernelBuffer&, size_t);
     [[nodiscard]] KResultOr<size_t> write(const u8* data, size_t size)
     {