libe2p: Declare prototypes for the journal feature name functions in e2p.h

Define the prototypes for e2p_jrnl_feature2string() and
e2p_jrnl_string2feature() in e2p.h.  This promotes better error
checking and avoids warnings when compiling the library and programs
that call these functions.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
1 file changed