nvme-core: fix memory leak in dhchap_secret_store

In the Linux kernel, the following vulnerability has been resolved:

nvme-core: fix memory leak in dhchap_secret_store

Free dhchap_secret in nvme_ctrl_dhchap_secret_store() before we return

fix following kmemleack:-

unreferenced object 0xffff8886376ea800 (size 64):

comm "check", pid 22048, jiffies 4344316705 (age 92.199s)

hex dump (first 32 bytes):

44 48 48 43 2d 31 3a 30 30 3a 6e 78 72 35 4b 67 DHHC-1:00:nxr5Kg

75 58 34 75 6f 41 78 73 4a 61 34 63 2f 68 75 4c uX4uoAxsJa4c/huL

backtrace:

[<0000000030ce5d4b>] __kmalloc+0x4b/0x130

[<000000009be1cdc1>] nvme_ctrl_dhchap_secret_store+0x8f/0x160 [nvme_core]

[<00000000ac06c96a>] kernfs_fop_write_iter+0x12b/0x1c0

[<00000000437e7ced>] vfs_write+0x2ba/0x3c0

[<00000000f9491baf>] ksys_write+0x5f/0xe0

[<000000001c46513d>] do_syscall_64+0x3b/0x90

[<00000000ecf348fe>] entry_SYSCALL_64_after_hwframe+0x72/0xdc

unreferenced object 0xffff8886376eaf00 (size 64):

comm "check", pid 22048, jiffies 4344316736 (age 92.168s)

hex dump (first 32 bytes):

44 48 48 43 2d 31 3a 30 30 3a 6e 78 72 35 4b 67 DHHC-1:00:nxr5Kg

75 58 34 75 6f 41 78 73 4a 61 34 63 2f 68 75 4c uX4uoAxsJa4c/huL

backtrace:

[<0000000030ce5d4b>] __kmalloc+0x4b/0x130

[<000000009be1cdc1>] nvme_ctrl_dhchap_secret_store+0x8f/0x160 [nvme_core]

[<00000000ac06c96a>] kernfs_fop_write_iter+0x12b/0x1c0

[<00000000437e7ced>] vfs_write+0x2ba/0x3c0

[<00000000f9491baf>] ksys_write+0x5f/0xe0

[<000000001c46513d>] do_syscall_64+0x3b/0x90

[<00000000ecf348fe>] entry_SYSCALL_64_after_hwframe+0x72/0xdc