fs/ntfs3: handle hdr_first_de() return value

fs/ntfs3: handle hdr_first_de() return value

[ Upstream commit af5cab0e5b6f8edb0be51a9f47f3f620e0b4fd70 ]

The hdr_first_de() function returns a pointer to a struct NTFS_DE. This
pointer may be NULL. To handle the NULL error effectively, it is important
to implement an error handler. This will help manage potential errors
consistently.

Additionally, error handling for the return value already exists at other
points where this function is called.

Found by Linux Verification Center (linuxtesting.org) with SVACE.

Fixes: 82cae269cfa9 ("fs/ntfs3: Add initialization of super block")
Signed-off-by: Andrey Vatoropin <a.vatoropin@crpt.ru>
Signed-off-by: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>