deps.ffmpeg: Remove extra parenthesis

[RytoEX]

Description

Remove extra parenthesis.

Motivation and Context

Noticed this while testing updates to dependencies. The current $Options array results in this set of arguments:

-DUSE_SHARED_MBEDTLS_LIBRARY:BOOL=OFF -DUSE_STATIC_MBEDTLS_LIBRARY:BOOL=ON) -DENABLE_PROGRAMS:BOOL=OFF -DENABLE_TESTING:BOOL=OFF -DGEN_FILES:BOOL=OFF

I thought the parenthesis seemed out of place, then checked, and found there was one extra here.

How Has This Been Tested?

Ran this locally:

.\Build-Dependencies.ps1 -PackageName ffmpeg -Target x64 -Dependencies mbedtls -Configuration Release -Debug

Build succeeded. I did not build OBS Studio against this yet.

Types of changes

• Bug fix (non-breaking change which fixes an issue)

Checklist:

• I have read the contributing document.
• My code has been run through clang-format.
• My code follows the project's style guidelines
• My code is not on the master branch.
• My code has been tested.
• All commit messages are properly formatted and commits squashed where appropriate.
• I have included updates to all appropriate documentation.