Use 'const' in 'buffer_peek_8', 'buffer_peek_le16'
Use 'const' in 'buffer_peek_8', 'buffer_peek_le16'

Signed-off-by: Jussi Virtanen <2a7e40f91a3be32dfb7e35af6e476a252ebdb4f3@gmail.com>

libtrading/libtrading,NunoEdgarGub1/libtrading,femtotrader/libtrading,svdev/libtrading,fengzhyuan/libtrading,penberg/libtrading,jvirtanen/libtrading,svdev/libtrading,penberg/libtrading,divaykin/libtrading,libtrading/libtrading,Bitcoinsulting/libtrading,jvirtanen/libtrading,etoestja/libtrading,NunoEdgarGub1/libtrading,femtotrader/libtrading,etoestja/libtrading,divaykin/libtrading,Bitcoinsulting/libtrading,fengzhyuan/libtrading,mstanichenko/libtrading,mstanichenko/libtrading