package/uboot-tools: drop redundant parentheses

package/uboot-tools: drop redundant parentheses

Commit d8db91fc6fa ("package/uboot-tools: resolve host uboot env/script
error") introduced closing parentheses that is not matched and not
needed.

Fixes:
http://autobuild.buildroot.net/results/a65/a65fcc581f56ef70154f83e80f12d64f2e0f856a/
http://autobuild.buildroot.net/results/39a/39aabb9d8afcdead1d620e081d2cd43ee2d61fbc/

Cc: Matt Weber <matthew.weber@rockwellcollins.com>
Cc: Kalpesh Panchal <kalpesh.panchal@rockwellcollins.com>
Signed-off-by: Baruch Siach <baruch@tkos.co.il>
Reviewed-by: Matt Weber <matthew.weber@rockwellcollins.com>
Reviewed-by: Bin Meng <bin.meng@windriver.com>
Tested-by: Bin Meng <bin.meng@windriver.com>
Signed-off-by: Yann E. MORIN <yann.morin.1998@free.fr>