schannel: drop fallbacks for unused BCRYPT_* macros

[vszakats]

In case they are used again in the future, the fallbacks are not
necessary for the supported mingw-w64 (v3+) and MSVC versions.

Follow-up to 6238888 #15621

[vszakats]

Hm, the commit message may be incorrect. VS2008 came with MS SDK 6.0a,
which is what we support now, and VS2010 came with MS SDK 7.0a, which is
soon to be the minimum. I need to get a copy of these old versions and recalculate.

Anyway these macros aren't used in the source, so the commit itself is fine.

[jay]

Here's the hashes from the official VS2010 ISOs (2010 original + SP1 ugprade) that I downloaded from MS technet.

$ sha256sum *.iso
fce24f0e3f95fdeb54b806be3266f3b61a1e6b5b78c7e6c13c36fc1a6f5ba0ad *VS2010SP1dvd1.iso
bdfba5df0bd72cffdb398fe885d9e36d052617647c0ae4fd0579a8fc785c95ba *en_Visual_Studio2010_Professional_x86_x16-81637.iso

Note if you are building a dev VM with versions older than that like 2008 I recall Microsoft used to warn to install in chronological order. For example 2005, 2005 service pack(s), 2008, 2008 service pack(s), 2010, 2010 service pack

[vszakats]

Got them, thanks a lot!

[vszakats]

These macros require MS SDK v7.0A (VS2010) or newer.