uri: put `inline` at beginning of strpbrk_or_eos declaration

Fixes:

      CC       uri.lo
    /home/smarchi/src/lttng-tools/src/common/uri.c:64:1: error: ‘inline’ is not at beginning of declaration [-Werror=old-style-declaration]
     static const inline char *strpbrk_or_eos(const char *s, const char *accept)
     ^~~~~~

Signed-off-by: Simon Marchi <simon.marchi@efficios.com>
Change-Id: I2f753143e65ac4301abc01fba3e9ef122b2d38b7
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>